1.
A small concentration of minority carriers is
injected into a homogeneous semiconductor crystal at one point. An electric field
of 10 V/cm is applied across the crystal and this moves the minority carriers a
distance of 1 cm in 20 µsec. The mobility in cm

^{2}/volt-sec will be
a.
1000

b.
2000

c.
5000

d.
50000

2.
The threshold voltage of an n-channel
MOSFET can be increased by

a.
Increasing the channel dopant concentration

b.
Reducing the channel dopant concentration

c.
Reducing the gate oxide thickness

d.
Reducing the channel length

3.
The forward dynamic resistance of a junction
diode varies ……………… as the forward current.

4.
The transit time of the current carriers through
the channel of an FET decides its ……………. characteristics.

5.
A p-type silicon sample has a higher
conductivity compared to an n-type sample having the same dopant
concentration. (TRUE / FALSE)

6.
Channel current is reduced on application of a
more positive voltage to the gate of a depletion mode n-channel MOSFET. (TRUE / FALSE)

7.
Match the following :

8.
Show that the minimum conductivity of an
extrinsic silicon sample occurs when it is slightly p-type. Calculate the
electron and hole concentrations when the conductivity is minimum. Given that µ

_{n}= 1350 cm^{2}/volt-sec, µ_{p}= 450 cm^{2}/volt-sec, and the intrinsic carrier concentration, n_{i}= 1.5 X 10^{10}cm^{-3}.
9. In the common emitter amplifier shown, the
transistor has a forward current gain of 100, and a base to emitter voltage of
0.6 volts. Assume I

_{CO}to be negligible. Choose value for R_{1}and R_{3}such that the transistor has a collector current of 1 mA and a collector to emitter voltage of 2.5 volts.**Solution :**https://www.youtube.com/watch?v=SjV5f5WC8GU